diff --git a/lib/rubella/weighting/per_value.rb b/lib/rubella/weighting/per_value.rb
index fa03fd8..abe4f2a 100644
--- a/lib/rubella/weighting/per_value.rb
+++ b/lib/rubella/weighting/per_value.rb
@@ -1,17 +1,37 @@
 module Rubella
   module Weighting
 
-    # Gets an input object and prepares the data for the output.
+    # The Rubella::Weighting object processes the given input data to an valid
+    # output processable Array. 
+    # These arrays contain a subarray for every unit of time. And these Array
+    # contain the buckets within the values for the output objects.
+    # The Weighting of the print intensitiy is done here, so that the output
+    # objects job is simply to print the stuff.
+    #
+    # The Rubella::Weighting::PerValue object weights every bucket set to 1 in
+    # ammount. So if you have have for example four cores, every core is
+    # weighted to 0.25 no matter how much the load of a single core is. It's
+    # just a "as is" weighting.
     class PerValue
       attr_reader :buckets
-      # : steps
+      # :steps
 
-
-      # buckets must be one of 1, 2, 5, 10, 20, 50 default is 10
+      # Constructor
+      # Creates a new Rubella::Weighting::PerValue object.
+      #
+      # @param buckets int must be one of 1, 2, 5, 10, 20, 50 default is 10
+      # @return Rubella::Weighting::PerValue
+      # @raise ArgumentError
       def initialize(buckets = 10)
         self.buckets = buckets
       end
 
+      # Creates a output readable list.
+      # This list is Array within a subarrays, which contain the buckets for
+      # every time value unit.
+      #
+      # @param input Rubella::Input An input object
+      # @return Array
       def parse input
         data = input.data
         # no data, no work
@@ -37,6 +57,10 @@ module Rubella
         data_list
       end
       
+      # Sets the buckets, if the value is valid
+      #
+      # @param buckets int The amount of buckets
+      # @raise ArgumentError
       def buckets= buckets
         # Must be divideable by 100
         if([1, 2, 5, 10, 20, 50].index(buckets) == nil)